I recommend you to read this article https://www.quicksprout.com/2012/11/05/image-optimization-102-the-advance-guide-to-seo-for-images/ and I hope that you will find some information on this topic! In this article described 9 ways to optimize an image for better search rankings.

- Optimize image size- Optimize image offline name (use relevant keyword as image offline name)- Right click on image then click on properties and select details tab then fill some image information there like - tags, title and more- After loading image on website use relevant keyword in image alt text- Use caption also- Submit image on image submission site

Image optimization can be done by defining alt tags to your images. This will help to read your images by search engine robots and index them in search engines. They also help to rank your images higher in search engines.